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Welding is one of the most important technological processes used extensively
in many branches of engineering, such as industrial engineering, shipbuilding,
pipeline fabrication, building bridges and others. The merits of such welded structures
include a high joint efficiency, water and air tightness, and low fabrication cost. It is one of
the most useful forces transmitting tool in engineering practice.
Kou and Le (1985) observed significantly improved weld structure and
properties, reduced solidification cracking, refinement in subgrain structure, reduction in
width of heat affected zone and improvement in strength and ductility due to low
frequency arc oscillation of 2014 aluminium weld.
Yoneda et al. (1991) investigated the primary crystal morphology and
the mechanical properties in hypoeutectic Al-Cu alloys (e.g., Al-6Cu, Al-11Cu,
Al-15Cu) vibrated mechanically during primary solidification. They also considered
the relationships between primary crystal morphology and the strength and
concluded that due to vibration, primary Al morphology is refined and distributed
uniformly and increasing frequency leads to increase in tensile strength of specimens.
Yamamoto et al. (1993) during their experimentation of vibrating molten
puddle with low frequency (10-30 Hz) pulsed MIG welding found grain refinement of
weld structure of commercially available Al-Mg alloy base metal (A5052) to wire. Due
to grain refinement there was an improvement in solidification crack susceptibility
of Al-Mg alloy weld metal. |
